1. Field of the Invention
A prosthetic ankle joint is provided with a tibial component, a talar component, and an intermediate sliding plastic bearing. The tibial component includes a depending peripheral wall that surrounds the bearing and is intended to reduce rubbing of the plastic bearing against tissue which could produce wear particles that lead to the formation of bone cysts. The peripheral wall is intended to reduce such possible abrasions by at least partially shielding the bearing.
2. Description of the Related Art
The existing Buechel-Pappas Total Ankle Replacement System, which was invented by the applicants of the subject invention, is a time-tested, total ankle replacement system which is a result of more than 30 years of development, clinical investigation, and use.
The Buechel-Pappas Total Ankle Replacement System is described in detail in U.S. Pat. No. 4,309,778 which is entitled “NEW JERSEY MENISCAL BEARING KNEE REPLACEMENT” which issued on Jan. 12, 1982, the disclosure of which is incorporated herein by reference.
The Buechel-Pappas Total Ankle Replacement System is also described in U.S. Pat. No. 4,340,978 which is entitled “NEW JERSEY MENISCAL BEARING KNEE REPLACEMENT” which issued on Jul. 27, 1982, the disclosure of which is incorporated herein by reference.
Notwithstanding the success of the Buechel-Pappas Total Ankle Replacement System which is the subject of U.S. Pat. Nos. 4,309,778 and 4,340,978, it has been discovered that for several reasons, including components that are too large and growth of tissue into the joint space between the components of the ankle prosthesis, rubbing of the plastic bearing against tissue produces wear particles. In turn, the wear particles lead to the formation of bone cysts.
It is the object of the subject invention to minimize this potential problem by providing a new and improved tibial component as part of the Buechel-Pappas Total Ankle Replacement System.
It is a further object of the subject invention to provide a new and improved tibial component of the Buechel-Pappas Total Ankle Replacement System which allows easy insertion of the intermediate plastic bearing during the surgical procedure of implanting the ankle in a patient.